The work in progress is an investigation of the development of children's communication ability. It is hypothesized that improvement over age on referential communication tasks is largely accounted for by children's growing understanding that referents must be carefully discriminated from similar non-referents. This process is termed comparison activity. Children who engage in comparison activity are expected to be more accurate communicators, be more effective in appraising their own or another person's communication accuracy and more successful in utilizing feedback from another person. Results from research conducted to date generally confirm these expectations. For example, children who are accurate communicators are also found to be more effective evaluators of their own or another person's communication performance. These data imply that common processes underlie performance on communication and appraisal tasks. Future research will explore the effects of training children in comparison activity and examine the efforts of training on communication accuracy, appraisal accuracy, and feedback utilization.